# What technique is used to exchange messages between two parties ensuring integrity? Discuss.

1. Using a ROT5 cipher encrypt the following plaintext. Prove your answer by showing the steps for both the encryption and decryption. (20 points)

Meet at the baseball field at three o’clock

Using a ROT3 cipher decry-pt the following ciphertext.

WKHF  RUYH  WWHL  VUHG

1. Following are two problems using a rail fence cipher. Prove both of your answers by showing the steps involved in encryption/decryption.  As [art of this problem you must also show the steps involved in reversing what you are being asked for.  (20 points)

Using a rail fence cipher with a depth of 2 encrypt the following message:

The bird is a raven

Using a rail fence cipher with zig zag pattern and a depth of 3 decrypt the following message:

MAEKN   ETTHPRAOEM  ETATP

1. This is a three part question. For each part the answer requires identifying an asymmetric encryption technique, hashing or both. As part of each question you need to discuss the technique to demonstrate your understanding of how the functionality (confidentiality, authenticity, integrity) is supported. You need to discuss the details of what the sender and receiver do and the key usage if applicable. (25 points)

1. What technique is used to exchange messages between two parties ensuring confidentiality? Discuss.

1. What technique is used to exchange messages between two parties ensuring authenticity? Discuss.

1. What technique is used to exchange messages between two parties ensuring integrity? Discuss.

1. Logical operations. Neatly align your result under the operands. (25 points)

Perform a logical AND on the following two binary strings:

1110111101110

0101011101001

Perform a logical OR on the following two binary strings:

1110111101110

0101011101001

Perform a logical XOR on the following two binary strings:

1110111101110

0101011101001 